Stator arrangement for an electric motor of a motor vehicle

Abstract

The invention relates to a stator arrangement for an electric motor of a motor vehicle, wherein the stator arrangement comprises a laminated core (2), several coil windings (3), a housing (1), a first sealing element (4) and a second sealing element (5; 6; 7), wherein the coil windings (3) are arranged in a cavity, wherein the cavity is sealed against an interior of the stator arrangement by the first sealing element (4) and by the second sealing element (5; 6; 7), wherein the first sealing element (4) is arranged in the laminated core (2), and wherein the second sealing element (5; 6; 7) is arranged between the housing (1) and the first sealing element (4).

Description

[0001] The present invention relates to a stator arrangement for an electric motor of a motor vehicle according to the preamble of claim 1.

[0002] Stator assemblies with cavities for winding heads sealed from the rotor are known from the prior art. A cooling fluid is used in these cavities to directly cool the winding heads, as such cooling is beneficial for the efficiency and continuous performance of the electric motor. The sealing from the rotor is intended to prevent the cooling fluid from entering the gap between the stator assembly and the rotor, thereby impairing the efficiency of the electric motor.

[0003] From DE 10 2020 117 266 A1 a stator arrangement for an electric motor with a carrier molded part which comprises a plurality of sealing seats on the radially inner side and corresponding sealing elements is known.

[0004] DE 10 2019 120 824 A1 discloses a canned motor having a housing and a stator arranged within the housing along a stator axis, which stator has a laminated core and a winding with winding heads arranged in a winding head space. The winding heads protrude from the laminated core at the end faces of the laminated core. Opposite the stator is a rotatably mounted rotor arranged along the stator axis in a rotor space. A can is arranged between the stator and the rotor. The canned motor has a seal for sealing the winding head space from the rotor space. The seal has a support region for supporting a support ring in the radial direction and a sealing region. The seal is arranged on an inner side of the can oriented towards the rotor.

[0005] From DE 10 2019 117 373 A1, a similar canned motor is known in which the support ring is made of a fiber-reinforced plastic which has a matrix material and first fibers and second fibers embedded in the matrix material. The first fibers are made of a first material and the second fibers are made of a second material which is different from the first material.

[0006] From https: / / wiki.polymerservice-merseburg.de / index.php?title=SHORE-Härte - Werkstoffentwicklung Elastomere&oldid=8947 it is known to use an elastomer with a SHORE hardness between 20 and 90 as a material for a seal.

[0007] In contrast, the present invention is based on the object of achieving a better seal of the cavity against the rotor.

[0008] This object is achieved by a stator arrangement according to claim 1, an electric motor according to claim 8, and a motor vehicle according to claim 9. Embodiments of the invention are specified in the dependent claims.

[0009] The stator arrangement comprises a laminated core, a plurality of coil windings, a housing, a first sealing element, and a second sealing element. The housing can, for example, surround the laminated core. The coil windings are arranged in a cavity. The coil windings can also be arranged in multiple cavities. A cooling liquid can be arranged in the cavity or cavities, which can be used to directly cool the coil windings during operation. The cavity is sealed from an interior of the stator arrangement by means of the first sealing element and the second sealing element. The rotor, for example, can be arranged in the interior, so that the cavity is then sealed from the rotor in order to prevent the cooling liquid from entering the gap between the stator arrangement and the rotor. The first sealing element is arranged in the laminated core. The second sealing element is arranged between the housing and the first sealing element.

[0010] This method achieves particularly good sealing, particularly due to the use and positioning of the second sealing element. Practical tests have confirmed this.

[0011] A cross-sectional size of the second sealing element in a first direction is smaller than a cross-sectional size of the second sealing element in a second direction. The second sealing element is arranged between the housing and the first sealing element in the first direction. The second sealing element is at least partially enclosed by the first sealing element in the second direction. It is particularly possible for the first and second directions to run perpendicular to one another.

[0012] It is also possible for the first direction to be radial and the second direction to be axial. The radial direction and the axial direction are defined by the rotational axis of the rotor located in the interior. The axial direction runs parallel to the rotor's rotational axis. The radial direction runs radially outward from the rotational axis.

[0013] According to one embodiment of the invention, the second sealing element can form two or more sealing planes with the first sealing element and / or with the housing. This also contributes to increasing the seal. If, for example, one of the sealing planes is overcome by the coolant, another sealing plane remains. Even if one of the sealing planes is damaged, for example, during assembly, the sealing effect is still maintained.

[0014] According to one embodiment of the invention, the interior space can be surrounded by the stator arrangement.

[0015] According to one embodiment of the invention, the second sealing element can be surrounded, in particular completely, by the first sealing element and the housing.

[0016] According to one embodiment of the invention, the second sealing element can be arranged within a recess of the first sealing element. In the context of this description, a recess is understood to mean, in particular, a passage through the entire first sealing element.

[0017] According to one embodiment of the invention, the second sealing element can be made of an elastomer, in particular ethylene acrylate rubber or fluororubber. These materials are particularly advantageous for providing good sealing performance, especially over the wide temperature range within which a motor vehicle is typically used. Furthermore, these materials are particularly chemically compatible with commonly used coolants.

[0018] According to one embodiment of the invention, the second sealing element can have a Shore hardness between 40 and 80, in particular between 45 and 75. Such a hardness is advantageous because the second sealing element can compensate for irregularities in the adjacent surfaces particularly well.

[0019] The electric motor according to claim 8 comprises a stator arrangement according to one embodiment of the invention and a rotor. The cavity is sealed from the rotor by the first and second sealing elements. For example, the rotor can be arranged in the interior.

[0020] The motor vehicle according to claim 9 comprises an electric motor according to an embodiment of the invention, which is designed to drive the motor vehicle.

[0021] Further features and advantages of the present invention will become clear from the following description of preferred embodiments with reference to the accompanying drawings. The same reference numerals are used for identical or similar features and for features with identical or similar functions. Fig. 1 is a schematic cross-sectional view of a section of a stator arrangement according to an embodiment of the invention; Fig. 2 a schematic detailed view of a cross section of a second sealing element according to an embodiment of the invention; and Fig. 3 a schematic detailed view of a cross section of a second sealing element according to an embodiment of the invention.

[0022] The stator arrangement comprises a housing 1, a laminated core 2, coil windings 3 arranged in a cavity, a first sealing element 4 and a second sealing element 5.

[0023] The cavity in which the coil windings 3 are arranged is sealed off from an interior space surrounded by the stator arrangement by means of the first sealing element 4 and the second sealing element 5. The first sealing element 4 is in contact with the laminated core 2. The second sealing element 5 is arranged radially inside the first sealing element 4 and is in contact exclusively with the housing 1 and the first sealing element 4. A part of the second sealing element 5 is arranged within a recess in the housing 1. The recess in the housing 1 is completely filled by the first sealing element 4 and the second sealing element 5.

[0024] Sealing the cavity from the interior is advantageous for direct cooling of the coil windings 3 with a coolant flowing within the cavity. This seal prevents the coolant from entering the gap between the stator assembly and the rotor, thereby impairing the efficiency of the electric motor.

[0025] The second sealing element 5 has a corrugated surface on both the side facing the first sealing element 4 and the side facing the housing 1. Due to the corrugated surface, the second sealing element 5 forms multiple sealing planes with the first sealing element 4 and multiple sealing planes with the housing 1.

[0026] The multiple sealing levels are particularly advantageous for a reliable sealing effect. If one of the sealing levels is overcome or damaged, for example, in the case of three sealing levels as in Fig. 1 two sealing levels are present, which ensure a reliable sealing effect.

[0027] In the axial direction, which runs parallel to the rotational axis of the rotor driven by the stator arrangement, the second sealing element 5 is larger in cross-section than in the radial direction, which runs perpendicular thereto and is also defined by the rotational axis of the rotor. In the axial direction, the second sealing element 5 is surrounded by the first sealing element 4. In the radial direction, the second sealing element 5 is arranged between the housing 1 and the first sealing element 4.

[0028] The larger axial extension is advantageous, for example, for achieving reliable sealing despite relatively large surface irregularities on the housing or the first sealing element. It also reduces the risk of axial tilting during assembly.

[0029] The second sealing element 5 is preferably made of ethylene acrylate rubber or fluororubber. This is particularly advantageous for a reliable sealing effect within a temperature range between -40 °C and 180 °C. Furthermore, these materials are particularly compatible with cooling fluids commonly used for direct cooling of the coil windings.

[0030] The material of the second sealing element 5 has a Shore hardness between 40 and 80, in particular between 45 and 75. This is advantageous for compensating for irregularities in the surfaces of the housing 1 and the first sealing element 4.

[0031] The Fig. The second sealing element 6 shown in Figure 2 also has a corrugated surface, the shape of which, however, differs from the shape of the corrugated surface of the second sealing element 5 Fig. 1. Radially outward, the second sealing element 6 forms a first number of sealing planes, namely three, with the first sealing element 4. Radially inward, the second sealing element 6 forms a second number of sealing planes, namely seven. Of the second number of sealing planes, a first subset is formed by the second sealing element 5 with the housing 1, and a second subset is formed by the second sealing element 5 with the first sealing element 4.

[0032] Due to the different number of sealing planes, the radially outer sealing planes are larger than the radially inner sealing planes. In practical tests, this design has proven to provide particularly good sealing.

[0033] The Fig. The second sealing element 7 shown in Figure 3 forms the same number of sealing planes, namely seven, radially outside and radially inside. Similar to the second sealing element 5 of Fig. 1, the sealing planes are of equal size. In contrast to the second sealing element 5 made of Fig. 1, a more reliable seal is achieved due to the higher number of sealing levels, but more installation space is required. Similar to the second sealing element 6 from Fig. 2 forms the second sealing element 7 Fig. 3 the sealing planes radially below partly with the first sealing element 4 and partly with the housing 1.

Claims

[1] Stator arrangement for an electric motor of a motor vehicle, wherein the stator arrangement comprises a laminated core (2), a plurality of coil windings (3), a housing (1), a first sealing element (4) and a second sealing element (5; 6; 7), wherein the coil windings (3) are arranged in a cavity, wherein the cavity is sealed from an interior of the stator arrangement by means of the first sealing element (4) and the second sealing element (5; 6; 7), wherein the first sealing element (4) is arranged in the laminated core (2), wherein the second sealing element (5; 6; 7) is arranged between the housing (1) and the first sealing element (4), characterized byin that a size of the second sealing element (5; 6; 7) in cross section in a first direction is smaller than a size of the second sealing element (5; 6; 7) in a second direction, wherein the second sealing element (5; 6; 7) is arranged between the housing (1) and the first sealing element (4) in the first direction, and wherein the second sealing element (5; 6; 7) is at least partially enclosed by the first sealing element (4) in the second direction. [2] Stator arrangement according to claim 1, characterized by that the second sealing element (5; 6; 7) forms two or more sealing levels with the first sealing element (4) and / or with the housing (1). [3] Stator arrangement according to one of the preceding claims, characterized by that the interior is surrounded by the stator arrangement. [4] Stator arrangement according to one of the preceding claims, characterized by that the second sealing element (5; 6; 7) is surrounded by the first sealing element (4) and the housing (1). [5] Stator arrangement according to one of the preceding claims, characterized by that the second sealing element (5; 6; 7) is arranged within a recess of the first sealing element (4). [6] Stator arrangement according to one of the preceding claims, characterized by that the second sealing element (5; 6; 7) consists of an elastomer, in particular of ethylene acrylate rubber or of fluororubber. [7] Stator arrangement according to one of the preceding claims, characterized by that the second sealing element (5; 6; 7) has a Shore hardness between 40 and 80. [8] Electric motor for a motor vehicle, comprising a stator arrangement according to one of the preceding claims and a rotor, wherein the cavity is sealed with respect to the rotor by the first sealing element (4) and the second sealing element (5; 6; 7). [9] Motor vehicle comprising an electric motor according to the preceding claim, wherein the electric motor is designed to drive the motor vehicle.

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